Smart cards are usually formed by a plate of plastic of perhaps 0.8 mm thickness, with an integrated circuit imbedded in the plastic and with contact pads on a bottom face of the card. Connections between a computer, vending machine, or other electronic device and the pads of the smart card are usually made by inserting the smart card into a card-receiving cavity of a connector. The connector is usually mounted on a circuit board, with contacts having tails soldered to traces on the circuit board and having pad-engaging ends positioned to engage the pads on the fully inserted card. A means is required to keep the card in the cavity after it has been fully inserted, and to later aid in retracting the card. A card connector of relatively simple and compact design, which included means for retaining and partially ejecting the card, where the means were of simple and compact design and easily operable, would be of value.
In accordance with one embodiment of the present invention, an apparatus for connecting to a smart card is provided, which is of simple and compact design, and which is constructed with simple mechanisms for retaining a fully inserted card, for easily releasing the card, and for partially ejecting the card when it is released to facilitate pullout of the card. The apparatus includes a housing forming a card-receiving cavity and a plate-shaped part of dielectric plastic material that holds contacts with pad-engaging ends that engage the pads on a card lying in the cavity. A card retainer is provided that has a largely rearwardly-facing shoulder at the front of the cavity to resist withdrawal of the card after it has been fully inserted into the cavity. A spring end lies at the rear of the cavity and is positioned to directly engage the card rear edge to urge the card forwardly out of the cavity. When the retainer shoulder is deflected, the spring automatically pushes out the card.
The card retainer is preferably formed by a sheet metal arm having a fixed end that is part of the housing, and a free outer end that is bent to form the shoulder and that can be deflected to remove the card from the cavity. The arm outer end has a tab that is positioned to be manually deflected, to move the shoulder out of the way of a card being moved forwardly out of the cavity. Upon such manual deflection of the tab on the arm, the spring partially ejects the card.
The spring can be formed by a bent wire with one end fixed against deflection and the opposite end lying in the rear of the cavity to be rearwardly deflected by a card during insertion and to thereafter push the card forwardly. The spring can be a coil spring with a front end of the coil spring pressing directly against the rear edge of the card. The spring can be formed by a part of a metal cover of the housing that is of spring temper and that forms a resilient leaf.
The arm of the card retainer can be formed integrally with a metal or plastic part of the card housing, and the arm can extend forwardly or laterally from its fixed end to its free end.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.